如何将颤动的 texteditingcontroller 值从一个无状态小部件传递到另一个无状态小部件答案

【问题标题】：How can I pass flutter textediting controller value from one stateless widget to another stateless widget如何将颤动的 texteditingcontroller 值从一个无状态小部件传递到另一个无状态小部件
【发布时间】：2021-08-17 17:51:25
【问题描述】：

这是 main.dart 文件：

import 'package:flutter/material.dart';
import 'package:untitled/button.dart';
import 'package:untitled/form.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[MyForm(), MyButton()],
        ),
      ),
    );
  }
}

这是 form.dart 文件：

import 'package:flutter/material.dart';

class MyForm extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    TextEditingController x = TextEditingController();
    return Container(
      child: Center(
        child: TextField(
          controller: x,
          decoration: InputDecoration(labelText: "Name"),
        ),
      ),
    );
  }
}

这里是 button.dart 文件：

import 'package:flutter/material.dart';

class MyButton extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Center(
        child: ElevatedButton(
          onPressed: () {
            //if I press this button the textediting field will show 10
          },
          child: Text("Pass 10"),
        ),
      ),
    );
  }
}

如果我按下 button.dart 中的按钮，如何在文本编辑字段中显示数据？
做这些事情的最佳方法是什么？
我应该在 statelesswidget 中使用 statefulwidgets 还是在 statefulwidgets 中使用 statelesswidgets？

我的想法是使用redux或provider来传递这种东西。虽然我不知道这个简单的东西是否需要状态管理系统。

【问题讨论】：

标签： flutter statefulwidget statelesswidget

【解决方案1】：

您需要提升状态（在主目录中创建您的控制器并将其传递给子节点）

// main.dart
class _MyHomePageState extends State<MyHomePage> {
  TextEditingController x = TextEditingController();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[MyForm(x), MyButton(x)],
        ),
      ),
    );
  }
}

class MyForm extends StatelessWidget {
  MyForm(this.x);
  final TextEditingController x;
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Center(
        child: TextField(
          controller: x,
          decoration: InputDecoration(labelText: "Name"),
        ),
      ),
    );
  }
}

class MyButton extends StatelessWidget {
  MyButton(this.x);
  final TextEditingController x;
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Center(
        child: ElevatedButton(
          onPressed: () {
            x...
            //if I press this button the textediting field will show 10
          },
          child: Text("Pass 10"),
        ),
      ),
    );
  }
}

【讨论】：